Recent trends in the telecommunications industry towards unified communications emphasize the need for converged networks to deliver acceptable quality of service (QoS) for different types of applications with varying QoS needs. Multimedia applications such as Internet telephony are among the end-to-end applications which demand strict QoS guarantees from the underlying data network. Understanding the network behavior at all stages of the deployment of such applications is critical for their performance. For example, at the pre-deployment stage, it is necessary to assess whether the network can deliver the required QoS and more importantly which parts of the network fail to do so. After deployment, monitoring the performance of the network is necessary for maintaining acceptable QoS levels.
Conventional network monitoring and analysis systems are generally not configured to provide an adequate mechanism for understanding link-level QoS behavior in a network. Such information is particularly useful for the purpose of locating the sources of performance problems in a network, but is also useful for many other purposes.
U.S. Patent Application Publication No. 2005/0053009, entitled “Method and Apparatus for Automatic Determination of Performance Problem Locations in a Network,” discloses techniques for automatically determining the particular locations associated with performance problems in a network comprising a plurality of endpoint devices. In one aspect, a network monitoring and analysis system is configured to include a root cause analysis function that permits the automatic determination of performance problem locations in the network. Test communications are generated in accordance with a selected pattern, and end-to-end path measurement data is collected utilizing the generated test communications. The test communications may be directed between pairs of the endpoint devices as specified in the selected pattern. The end-to-end path measurement data is transformed to produce performance indicators for respective non-end-to-end paths defined at least in part by the selected pattern. Such an approach advantageously provides a particularly efficient and accurate mechanism for generating link-level performance indicators in a network, thereby permitting a better understanding of QoS behavior in the network.
Despite the considerable advances provided by the techniques disclosed in the above-cited U.S. patent application, a need remains for farther improvements, particularly with regard to root cause analysis of network performance problems.